Arrangement of sound transmitters and sound receivers on ships



H. HECHT Aug. 23, 1932.

ARRANGEMENT OF SOUND TRANSMITTERS AND SOUND RECEIVERS ON SHIPS FiledNov. 16. 1928 @41 1 nd starboard.

Patented Aug; 23, 1932 e l t RAi mmn "The invention relates toai'qaaintie xleitlys e531- Vantageous arrangement. of semi" transmit;-

fiersqr soundreceiverson gships;l The invenv tien is based JupQn'theiobsermtion that; en? teaching: certain speeds of travel; WhIGhqlIIthe case of difierent typesb1sliips 1 2E69 vaiiou's values; it is notpossible to transmit signals from theship in the aft dimeetipn within aeertaingangulari zone er. to irecelx e 1 Signals fromatransmitteralocated withinthls?" Zone. 1 The-reason for thisphenomenon? Wavy-t i "probably residesinzthe fectthat awolume QtWatencatriedelong byithe; ship in thellfilghf beurhood ofthe sternpqsjti begins 1391 :be res intq turbulent circulation land is eenvertedinto, aj inixtureefwater: andmirmimpermeehle;

vAcqordingr to the invention this diflienlty; is overcome bya ranging, adevice both-anthe pert side 1 and a t-wthe starboard sideetjthe;

widest Point of the, ship; andappr0p i te1-y- 0114a carrier thatprojects, trounce-9am be moved out ofthe outer -,skin% of; the ship: Iti

i isdesirabmet;theg meztim to'maike us aelsoi fo elot the sp-fialledgizenp arrangements soun toibe; n entretedehieflyjn artieulen directiqnsor o be-mceived ch fly'f mwpektieulardineetiena .7: {1he inv ent-ionis:expleinedwvith:the:ai limr r w ng in greater d il I1ithHfOl1QWlfiga e cniptibn-fwm s Eigs hews iag emme iee yawh Jeane 1 "3Bgens tatthestermpost at low speeds;ef tizevel @F g-A- howswhethappen epne h eri eal-speed f a-tnaveli when-using a t-lzanjsmitter arranged thelongitudinal axisof the ehig; and "a pain of transmitters arranged etgpntf .uEig 3: an 'fd how'ii egmmmatieallw transmitter w arrangements;\aeeorfling to the intenti nq k v p and: 6 ShQi Q PQ Q-Yt i l t-lmgifil dimi .smellwlgendalargei scalelrespeetiyee 319,531Qfagi 1? in Qeif ixenyi-lfji'ember 25; 1 92?: ly the eenstmietien-nf one? of thesound? de'- Vieeslil, l2, 13efFig. 4; and themanner in which; they areinserted into the" devie 14 of Eig l gend Figs.-7 and18 show diflerent,phgase relejtiensflof gtlie. tlwo soundwaves:

emanatingfiromgtwo;transmitters. InFi-g '1, 1 shows the outlineof mship}in the midkile ofithe bettomj ofwhie'h is 110 cated awtransmittei 2.1When travelling;

theqshi'p drags a mere oniless :largeymassibfi water :3 behind in which,however, etirela tivelylqlow "speeds still consists of. acoustical clearwater; A Sound emit-ted fionirthe transmitten 2,1 in this condition,penetrates this mass? of Water still unwea'kened as mp resented bythemadial lines, drewn ascarrolwsr Oin; exceeding the, criticaljspeed Qftravel, the. masjsuof-qwater ,3 suddenly loegins tdrbe: releasedfrom-therearend.oftheiship endto tujrn integer turbulent .circulation.this Q5. 7

phenomenon-0t econsticgwmtes? intersect close behind thejship point b);so that atherefre the? signals: can "already be heard ,eyen at ai mqderate'idistence; (fol-(instanceseverelxships 1engl1s)tl1e ship5in any.direetion, and? vice-verse also signals coming from there tgth'eshiprean: be; pi ke p, by1a1sing=1-;E6r reeeptiom eithefithe ione.1.01? the othereappare his or gheth- .llhe:"xeorrectness and:praeticeb ll keel line formation.

In Fig. 3, arrangements of sound apparatuses on protrudable members areillustrated diagrammatically, and 8 constituting the members, each ofwhich is equipped near its end with a sound device. V In Fig, 4 areillustrated two protrudable members arranged in the same way eachequipped with a group of sound; devices. Each member contains in thiscase ,three sound devices which are indicated by hatched 7 lines at'll',12and 18; The mounting of these; sound devices isshown more detailedtrudable device or sword lltof'Figl fl is shown, and Fig.6 shows furtherdetails in cross-section of the manner in which such a sound'device isfastenedi'In these figures- 17 18 represent the two diaphragms which-turejs 22 and 23- coupled respectively with' are arranged flush withthe surface of the sword 14. These diaphragmsconstitute the sides of acasing 19 which contains the arma' diaphragms 17 and 18; These armaturesare jointly energized by coil 24 which is con nected bycables (shown indotted lines in Fig. 4:) passing through the hollowsword l i'with theapparatus shown in' Fig.' 4. As-

shown in Fig.- 6 each casing 19 isinserted into a transverse openingprovided in sword' 14:

and heldtherein by flush rings 20 and 21* which maybe either threadedinto orbolted to the sword (not shown) These details describedhereinbefore form, however, no part of the presentinvention. Thus,usei's made here of the well-known group arrangement of-the sound de'vices spaced in a vertical 1 pose, '14 and: 15- indicate' simple movablemechanisms (rack and toothed wheel) with.

the aid of whichjthe apparatus can be moved in'theigland lG. J i I y r 1()fcourse,'if required,"group arrangements differently disposed withregard to number and position can also be used. Likewise the.

type of the sound device itself'is immaterial :30 them unite c fortheinvention; Itisonly essentialthat thesound apparatuses are'used in;pairs and are placed asmuch as possible on to the out- V ermost ends of'thelargest beam of thehull and actually in such aposition with respectto the acoustically turbid layer of the wake that the sound 'beams'toaft emitted from' behind the, acoustically turbid layer.

I -On account offthe'simultaneous radiation of twotransmitters',ifthelatter areworked absolutely in'phase, interferences r'night oc-four in the sound field, which "might lead to deadsound spots at definitepoints of the sound field. For instance, as shown in Fig. 7, the soundwave emanating from one trans It is obvious" not .be energizedfrom thesame source of alternating current, as would appear obvious,

but fro'm two sources of alternating current i entirelyindep'end'e'ntiof'one another as shown in'Figfi. Two of-such sources arenever conin 'Fig's..5 and 6. In'FigJ5 the general arm nt of thesonn d vc i -..the P TO:

tiniiously inph'ase or of the same frequency ian gt e forma 0111 7 xed.d ad-"point is 'irnpossible.

011, reception,' particularly inthecase'of an unknown position of thetransmitter to be" picked up, likewise both apparatuses would b'eu'sed;Alsoin this case-interferences are possible Land in order to avoidcomplete eX-- tmction 1t'1s desirable toallow the receiverto work onthe-telephone with a considerable d-ifieren ce of'energy (1: 2 or'more).

"j'lhe reasons forgthis expedient are as follows If sound is receivedfrom a source of sound' (for instance a submarine transmit-' ter), whoseposition is'gunknown, it could happen, if the "reception 'is'made withonly,

one instrument, that the' sh'adow zones of the wakelie between "thetransmitter the re ceiven For this reason, at least "at the begin ning,reception must be carried 'on'wit'h both receivers o'njboth sidesof theshipY-Then correct reception is always insured, because theinstrumentsare arranged sov that even in the most unfavorable positionof the sound; source'to bere'ceived at leastone receiver will" be'struck by the sound wa ve.; "lf now'both I soundjwave received by thestarboard instru me'nt. Both have the amplitude a withoppO- site phaseandtheireffect' would thus amount to zero. 'I-ffori' the other handftheenergies received by thetwo 'sound "apparatuses are" transmitted to thetelephone :atadi-ii'erent magnitude relatively to each other a'cOndition will exist as is illustrated in'Fig. 8 oftlie enclose'dske'tch" Therethe port instrument may transmit its energy to thetelephone at the amplitude 04 and the starboard instrument at b ,fstillass ming that they 'arereceivedat opposite phase Inl' thisc'ase theamplitude difi'erence a-b, namely the amplitude 0 i on ships in motionundisturbed by the ships wake, comprising sound transmitting and re-'ceiving devices spaced apart as far as possible to portand starboard,to cause the sound waves to straddle theships wake, said de- 15 vicesbeing so arranged as to project below the bottom of the ship.

2. An arrangement for submarine transmission of sound on all sides of aship in motion, undisturbed by the ships wake, in-

eluding a ship, sound transmitting devices mounted on the ship and beingspaced apart as far as possible to portand starboard to cause the soundwaves to straddle the wake, and being so arranged that they projectbelow the bottom of the ship, different means, independent of oneanother for supplying alternating current of ever varying frequency toeach sound transmitting device at the same time to maintain an evervarying phase relation between the two sources.

3. An arrangement for submarine reception of sound on all sides of aship in motion, undisturbed by the ships wake, comprising soundreceiving devices spaced apart on the ship as far as possible to portand starboard,

to permit reception of the sound waves which straddle the wake, saiddevices being so arranged that they project below the bottom of theship, and a common indicator connected to both receiving devices, andmeans for varying the amount of energy supplied to the indicator by onedevice with respect to that supplied by the other, whereby differentamounts of energy are received by said indicator at the same time.

In testimony whereof I aflix my signature.

HEINRICH HEOHT.

